So how does China's stealth aircraft measure up against America's F-22? After all, the F-22 was designed to be the United States' "air superiority" fighter for the next few decades. The US Air Force has bought 187 of them at about $150 million a pop, so us taxpayers better hope we got out moneys worth. While there are many things we do not know about China's J-20 stealth fighter, we can reasonably compare it with the F-22 and see if this Chinese fighter really lives up to the hype.
Range and Armaments: J-20 Wins
The J-20, according to measurements done by various experts, is a bigger beast than the F-22. In the world of aircraft, lanrge size means more room for missiles and fuel. Therefore, it is reasonable to assume that it has a longer range and/or more missile carrying capacity. That depends, of course, on the weight of the aircraft, and the efficiency of the engines. The F-119 that powers the F-22 is highly efficient...the Chinese are unlikely to match it anytime soon. But a few extra kilometers of range and two more missiles could give the J-20 the decisive edge it needs.
The J-20, according to measurements done by various experts, is a bigger beast than the F-22. In the world of aircraft, lanrge size means more room for missiles and fuel. Therefore, it is reasonable to assume that it has a longer range and/or more missile carrying capacity. That depends, of course, on the weight of the aircraft, and the efficiency of the engines. The F-119 that powers the F-22 is highly efficient...the Chinese are unlikely to match it anytime soon. But a few extra kilometers of range and two more missiles could give the J-20 the decisive edge it needs.
Speed: Toss up
One of the most amazing attributes of America's F-22 is its ability to "supercruise." What does that mean? It means that the aircraft can break the sound barrier without engaging the engines' afterburners (adding fuel to the exhausts). Despite what you see in the movies, a fighter jet can only break the sound barrier for a limited amount of time, because the afterburners will literally burn through all the fuel. The F-22 uses two F-119 jet engines, each producing over 150 kN of thrust with a thrust to weight ratio of at least 9:1. That, combined with lightweight composite materials in the airframe, means that the F-22 doesn't need an afterburner, and therefore can save a lot of fuel in high speed engagement. China's J-20 is longer and more slender than the F-22, indicating that it is designed for sustained supersonic flight. However, right now we know little about the engines. From the footage of the first flight, we can see that there are no flames emanating from the exhausts...meaning no afterburner was engaged. This is quite a feat given that the plane in larger than the F-22, but China is known for having trouble developing reliable jet engines. It's safe to say that theoretically the J-20 could outperform the F-22 in supercruise, but until we have more information on the engines we cannot say for sure.
One of the most amazing attributes of America's F-22 is its ability to "supercruise." What does that mean? It means that the aircraft can break the sound barrier without engaging the engines' afterburners (adding fuel to the exhausts). Despite what you see in the movies, a fighter jet can only break the sound barrier for a limited amount of time, because the afterburners will literally burn through all the fuel. The F-22 uses two F-119 jet engines, each producing over 150 kN of thrust with a thrust to weight ratio of at least 9:1. That, combined with lightweight composite materials in the airframe, means that the F-22 doesn't need an afterburner, and therefore can save a lot of fuel in high speed engagement. China's J-20 is longer and more slender than the F-22, indicating that it is designed for sustained supersonic flight. However, right now we know little about the engines. From the footage of the first flight, we can see that there are no flames emanating from the exhausts...meaning no afterburner was engaged. This is quite a feat given that the plane in larger than the F-22, but China is known for having trouble developing reliable jet engines. It's safe to say that theoretically the J-20 could outperform the F-22 in supercruise, but until we have more information on the engines we cannot say for sure.
Maneuverability: J-20 Wins
The F-22 is, in aerodynamic terms, fairly conventional. It has all the same control surfaces that one might find on the F-15. However, it does have something that the F-15 does not: thrust vectoring. Thrust vectoring, simply put, is the ability to alter the direction of exhaust nozzles, thereby directing the exhaust and allowing the aircraft to perform maneuvers that it otherwise could not. The F-22 features a "two-dimensional" thrust vectoring system; the nozzles can deflect the exhaust up or down by up to 15 degrees. Thus, the F-22 can out-maneuver an F-15. How does China's J-20 measure up? The J-20 has all the same control surfaces that the F-22 does. Additionally, the J-20 has all moving vertical stabilizers (which gives them more surface area and hence deflection power) and canards (the small 'wings' near the front of the plane) both of which the F-22 lacks. This could, in theory, give the J-20 a decisive edge. Additionally, the J-20 is presumably using "three dimensional" thrust vectoring, which can alter the direction of the exhausts in ANY direction, not just up and down as seen in the F-22. This is a clear win for the J-20
The F-22 is, in aerodynamic terms, fairly conventional. It has all the same control surfaces that one might find on the F-15. However, it does have something that the F-15 does not: thrust vectoring. Thrust vectoring, simply put, is the ability to alter the direction of exhaust nozzles, thereby directing the exhaust and allowing the aircraft to perform maneuvers that it otherwise could not. The F-22 features a "two-dimensional" thrust vectoring system; the nozzles can deflect the exhaust up or down by up to 15 degrees. Thus, the F-22 can out-maneuver an F-15. How does China's J-20 measure up? The J-20 has all the same control surfaces that the F-22 does. Additionally, the J-20 has all moving vertical stabilizers (which gives them more surface area and hence deflection power) and canards (the small 'wings' near the front of the plane) both of which the F-22 lacks. This could, in theory, give the J-20 a decisive edge. Additionally, the J-20 is presumably using "three dimensional" thrust vectoring, which can alter the direction of the exhausts in ANY direction, not just up and down as seen in the F-22. This is a clear win for the J-20
Radar: F-22 Wins
The F-22 employs an advanced radar system called Active Electronically Scanned Array (AESA) radar. Such radar systems require no moving parts, therefore last longer and require less maintenance. These radars are more powerful as well, allowing for greater detection ranges and better multi-target tracking capability. Now if the J-20 really is bigger than the F-22, there is a good chance the nose of the plane would be large enough to accommodate a larger (and therefore more powerful) radar system. This cannot be substantiated, but we do know that China has AESA technology, and will be using it on the J-20. That said, a modern radar's effectiveness is judged more by software, not hardware. The US has more experience in AESA radars and has had more time to refine its software. Again, we cannot say for sure which will be "better," but for good measure I think we can give it to the F-22.
The F-22 employs an advanced radar system called Active Electronically Scanned Array (AESA) radar. Such radar systems require no moving parts, therefore last longer and require less maintenance. These radars are more powerful as well, allowing for greater detection ranges and better multi-target tracking capability. Now if the J-20 really is bigger than the F-22, there is a good chance the nose of the plane would be large enough to accommodate a larger (and therefore more powerful) radar system. This cannot be substantiated, but we do know that China has AESA technology, and will be using it on the J-20. That said, a modern radar's effectiveness is judged more by software, not hardware. The US has more experience in AESA radars and has had more time to refine its software. Again, we cannot say for sure which will be "better," but for good measure I think we can give it to the F-22.
Cockpit Design: J-20 wins.
The F-22 was a revolutionary machine for its use of a high tech "glass" cockpit. The F-22 eliminated virtually all the knobs and buttons seen on older fighters, replacing them with several LCD screens that reduce pilot work-load and increase pilot situational awareness. By integrating man with machine more seamlessly than ever before, the F-22 would become a far more formidable weapon. However, China's J-20 has the advantage of being designed later therefore can take advantage in improvements in software and electronics. If the cockpit designs shown at the Zhuhai Air-show are any indication, the J-20 will have cockpit that is even more "glassy" than the F-22. This is likely a win for the J-20.
The F-22 was a revolutionary machine for its use of a high tech "glass" cockpit. The F-22 eliminated virtually all the knobs and buttons seen on older fighters, replacing them with several LCD screens that reduce pilot work-load and increase pilot situational awareness. By integrating man with machine more seamlessly than ever before, the F-22 would become a far more formidable weapon. However, China's J-20 has the advantage of being designed later therefore can take advantage in improvements in software and electronics. If the cockpit designs shown at the Zhuhai Air-show are any indication, the J-20 will have cockpit that is even more "glassy" than the F-22. This is likely a win for the J-20.
Infrared Stealth: F-22 Wins.
Contrary to popular belief, stealth aircraft are not only trying to reduce their appearance on radar. Engineers also painstakingly try to figure out ways to reduce the appearance of an aircraft in the infrared spectrum. In other words, reduce the amount of heat given off by an aircraft's jet engines, thereby making it harder for heat seeking missiles to take it down. The F-22 employs an advanced exhaust cooling system combined with a rectangular exhaust nozzle design to mix the hot jet air with the cold high altitude air very quickly. In doing so, the visibility of the F-22 to a heat-seeking missile is greatly reduced. The Chinese J-20 has a standard circular nozzle, but is said to employ "stealth nozzle technology." The nozzle features an advanced cooling system similar to that used on the F-35. Sadly, this is a newer technology that was not around when the F-22 was being designed. Nevertheless, the F-22's rectangular nozzle gives it a small advantage. This one goes to the F-22.
Contrary to popular belief, stealth aircraft are not only trying to reduce their appearance on radar. Engineers also painstakingly try to figure out ways to reduce the appearance of an aircraft in the infrared spectrum. In other words, reduce the amount of heat given off by an aircraft's jet engines, thereby making it harder for heat seeking missiles to take it down. The F-22 employs an advanced exhaust cooling system combined with a rectangular exhaust nozzle design to mix the hot jet air with the cold high altitude air very quickly. In doing so, the visibility of the F-22 to a heat-seeking missile is greatly reduced. The Chinese J-20 has a standard circular nozzle, but is said to employ "stealth nozzle technology." The nozzle features an advanced cooling system similar to that used on the F-35. Sadly, this is a newer technology that was not around when the F-22 was being designed. Nevertheless, the F-22's rectangular nozzle gives it a small advantage. This one goes to the F-22.
Radar Stealth:
This category is the most interesting, it is also among the most difficult to judge. Contrary to popular belief, stealth aircraft are not 'invisible' to radar. Instead, engineers use clever tricks to reduce the radar signature of an aircraft so that it appears to be a bird or perhaps even an insect on the enemies scopes. How do they do this? Well, first you need a basic overview of how radar works:
This category is the most interesting, it is also among the most difficult to judge. Contrary to popular belief, stealth aircraft are not 'invisible' to radar. Instead, engineers use clever tricks to reduce the radar signature of an aircraft so that it appears to be a bird or perhaps even an insect on the enemies scopes. How do they do this? Well, first you need a basic overview of how radar works:
A radar transmitter sends out a pulse of radar waves through the air. If there is a solid object in the sky, such as an aircraft, radar waves will bounce off of it and reflect back from whence they came.A receiver can detect the reflected radar waves and determine the size, speed, and distance that object is from the transmitter.
Stealth aircraft are designed so that the aircraft either absorbs or reflects radar waves away from its source. For purposes of comparison, I will break down the various methods, comparing the merits of the F-22, J-20, and why not, the Russian T-50 (Russia's stealth aircraft being developed in conjunction with India).
LPI Radar- F-22=Yes, J-20=Yes, T-50=Yes
Opaque Radome- F-22=Yes, J-20=Yes, T-50=Yes
Chined Nose- F-22=Yes, J-20=Yes, T-50=Yes
Frameless Cockpit Canopy- F-22=Yes, J-20=Yes, T-50=No
Opaque Cockpit Canopy- F-22=Yes, J-20=Yes, T-50=Yes
Serpentine Intakes- F-22=Yes, J-20=Yes, T-50=No
Canted Vertical Stabilizers- F-22=Yes, J-20=Yes, T-50=Yes
Internal Weapons Bay- F-22=Yes, J-20=Yes, T-50=Yes
Blended Fuselage/Wings- F-22=Yes, J-20=Yes, T-50=No
Smooth Skin Lacking Significant Protrusions- F-22=Yes, J-20=Yes, T-50=No
Serrations on Weapons Bay/Landing Gear Doors- F-22=Yes, J-20=Yes, T-50=No
Opaque Radome- F-22=Yes, J-20=Yes, T-50=Yes
Chined Nose- F-22=Yes, J-20=Yes, T-50=Yes
Frameless Cockpit Canopy- F-22=Yes, J-20=Yes, T-50=No
Opaque Cockpit Canopy- F-22=Yes, J-20=Yes, T-50=Yes
Serpentine Intakes- F-22=Yes, J-20=Yes, T-50=No
Canted Vertical Stabilizers- F-22=Yes, J-20=Yes, T-50=Yes
Internal Weapons Bay- F-22=Yes, J-20=Yes, T-50=Yes
Blended Fuselage/Wings- F-22=Yes, J-20=Yes, T-50=No
Smooth Skin Lacking Significant Protrusions- F-22=Yes, J-20=Yes, T-50=No
Serrations on Weapons Bay/Landing Gear Doors- F-22=Yes, J-20=Yes, T-50=No
I wont go into detail why each of the above features are required to ensure stealth, but as we can see, both the F-22 and J-20 meet every requirement, making them true stealth aircraft. The Russian T-50 fails to meet five out of eleven of the features listed here. Of course, these are not the only requirements that a stealth aircraft must meet, but it's a fairly comprehensive list for comparison purposes.
The J-20 has another feature that the F-22 lacks...DSI intakes. The F-22 uses fairly standard intakes which direct the flow of oxygen into the engines. This requires a complex system of moving parts...which add weight and increase maintenance costs. The J-20 uses a more advanced type of intake called a DSI intake, or Diverterless Supersonic Intake. This type of intake is better for stealth, lighter, and has zero moving parts. This gives the J-20 another advantage over the F-22. Overall however, this category is a toss up because the F-22 does a better job at hiding its engine nozzles from radar.
At this point it is impossible to make a full comparison between these two machines as much is not yet known. But it is clear that China is establishing itself as a innovation superpower. While the US has always led the aerospace industry (and still does) the Russians always trailed behind in second place. China, for decades, simply copied older Russian designs, attempting to stay competitive. The J-20 has changed the aerospace landscape, it is neither a copy nor does it trail the Russians. In fact, the Russian T-50 is, by all measures... inferior. China has vaulted ahead of Russia in aerospace prowess (why else do you think the Chinese media is so keen to show off their latest creation?) The J-20 is a worthy competitor to the F-22, perhaps equaling it in performance, quite an amazing feat by a country that a decade ago was still copying Mig 21s.
Article Source:http://goarticles.com/article/J-20-VS-F-22-A-Direct-Comparison-of-China-s-and-America-s-Stealth-Fighters/4207993/
